The present invention relates generally to the field of wood chip processing, and more particularly to a machine and associated method for dense packing of wood chips for storage, transport, or further processing.
One major factor in the cost of wood chips for paper making is the cost of transporting the wood chips from the chip manufacturing site to the paper mill. The wood chips are typically transported in rail cars, but may also be transported in barges, trailers, or the like. Typically, the transportation costs are based primarily on the number of containers used to ship a given load of wood chips. As more densely packed containers means that fewer containers are required to ship a given amount of wood chips, it follows that more densely packed containers will generally supply more useable wood chips to the paper mill at a lower transportation cost.
Space considerations are also relevant in the storage and processing of wood chips. For instance, the storage of wood chips on site, such as at a pulp mill, consumes space. As such, it is advantageous to have the wood chips densely packed when “stacking” the wood chips for storage. Similarly, many methods of processing wood chips include batch processing steps that take place in pressure vessels, or other containers, that have fixed volumes. If additional wood chip materials can be packed into the containers, the batch process can likely be made more efficient.
Even with these considerations, many wood chip transporting, storing, and/or processing approaches rely on either conventional free-fall techniques or on techniques that result in packing densities of typically not more than 17% improvement over free-fall techniques.
Accordingly, there remains a substantial need in the industry for alternate wood chip handling techniques that allow for higher packing densities.